Building panel as structure of outer and inner plate with intermediate insulation space

ABSTRACT

The building panel is structure of outer ( 11 ) and inner ( 12 ) plate where there is intermediate insulation space between the plates ( 11 ) and ( 12 ). In this space there can by any kind of thermal and/or sound insulation which does preferably not form solid structure in connection with plates ( 11 ) and ( 12 ). The connection ( 1 ) forms connection between plates ( 11 ) and ( 12 ). The connection ( 1 ) is implemented at least along the longitudinal part of panel frame. Further the connection ( 1 ) comprises the attached polymer-based profile ( 2 ) or stack of spacers ( 7 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a §371 National Phase Application of PCT/SI2011/000009, filed on Feb. 19, 2011, which in turn claims priority from Slovenian Patent Application P-201000320 filed Oct. 15, 2010, both of which are incorporated herein by reference

FIELD OF THE INVENTION

The Present Invention is classified as technical solutions of civil engineering with integral thermal and sound insulation, performed using principles of composite, pre-fabricated panel, with side frame based on polymers and steel metal sheets, said panel to be used in building shells-integrated and hanged facades.

BACKGROUND OF THE INVENTION

Facing diminishing stock of liquid fossil fuel which as the most user-friendly energy form, our civilization faces need for new ways of using remaining sources of energy. One of the ways is to decrease the use of energy for heating, cooling, and erecting of buildings. The thermal insulation of buildings is important for achieving a decrease in energy use. Increase in need for effective thermal insulation resulted in insulation systems with low thermal conductivity. Such systems are based on composite panels using vacuum panels, nanofoams, aerogels or gas filled composites for their insulation core. The building panels using these cores usually cannot utilize these cores for providing of load carrying capability or stiffness of said panels due to mechanical weakness of such insulation cores.

State of the art features three groups of relevant panels. The first group shows panels with various implementations of polymer border/reinforcement of composite building panels: EP1333129, GB2344834, GB2451275 and WO2005/070803. Particularly important seem subgroup of patents where the polymer border/reinforcement is combined with inner steel reinforcement: FR2813624, US2004/0231275 and U.S. Pat. No. 4,993,204. The second group comprises patents where the panel is build based on steel reinforcement or spacers: EP1312725, WO1998/45545. The third group comprises of patent discussing choice of adhesive for connection of elements of the first and the second group: W02004/073973.

Patent FR2813624 describes polymer reinforcement which quite effectively prevents excess heat transfer and provides for suitable reinforcement with combination with steel reinforcement profiles for panels which are additionally supported with load carrying insulation core. For use of non-load carrying insulation cores such as necessary in above referenced technical problem, use of simple thermoplastic extrudates such as for example PVC according to patent FR2813624 is not sufficient from the viewpoint of panel stiffness, and does not provide for match in linear temperature coefficients of expansion. The use of PVC would provide an increased use of inner steel reinforcement which would be detrimental to very desirable heat resistance of this reinforcement.

Patent EP1333129 suggests use of glass reinforced pultruded profiles which may be used for panels with load carrying core without steel inner reinforcements, however this solution could not be used for a system without load carrying core.

Patent W02004073973 defines adhesive for attaching of side frame as follows: the adhesive should be from polyurethane, epoxy or methacrylate group. The adhesive should have tensile and/or shear strength at least 2 MPa. In our research we have shown that the adhesive having strength only at least 2 MPa does not satisfy criteria for use in building panels. Our experiment used polyurethane adhesive with strength significantly over 2 MPa and with modulus of elasticity over 1000 MPa. After attaching the panel onto the building the outer panel fell off after approximately 2 months in summer. Hard polymer adhesives with high modulus of elasticity after exposure to varying day temperatures between 10° C. and 75° C. or more show loss of adhesive properties. This fact has been known for some quite time with structural insulation glass coverings without a load carrying insulation core where exterior glass is only attached using soft silicone adhesives with a modulus of elasticity up to 1.5 MPa or hardness 20 to 35 Shore A. However in insulating glass technology the glass itself does not provide for stiffness of the glass panel. The stiffness is provided with large metal elements, usually found in entirety on the inner side of the building.

SUMMARY OF THE INVENTION

The goal of presented invention is to propose such construction of composite panel where outer and inner plates provide for a stiff box structure of a building panel utilizing a side frame, said building panel comprising optional insulation core. The frame must provide for stiffness of said panel with a mechanical link between the inner and outer plates and with its own stiffness. The frame should, if possible provide for effective inhibition of heat transfer and provide for dilatation of panels due to temperature difference within buildings, in particular on their exterior.

The above referenced technical problem is solved by building panel as structure of outer and inner plates with intermediate insulation space. According to the invention the problem of building panel is solved by using outer and inner plates attached by solid structural connection. The structural connection is attached to the plate with adhesive of appropriate thickness and hardness according to implementation of the invention. The building panel is a structure of outer and inner plates whereas between the inner and outer plates and there is intermediate insulation space with any kind of thermal and/or sound insulation preferably not forming a solid structure in connection with plates and. The connection comprises the link between the inner and outer plates. The connection is implemented at least along the longitudinal part of panel frame. Further, the connection comprises an attached polymer-based profile in a first embodiment or spacer stack in a second embodiment, comprised of at least one spacer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cutaway view of a first embodiment of the present invention, where the building panel is a structure of outer (11) and inner (12) plates, the outer plate for example of glass, and inner for example dry wall.

FIG. 2 is a partially cutaway view of a second embodiment of the present invention, where the building panel is a structure of outer (11) and inner (12) plates with intermediate insulation space.

DETAILED DESCRIPTION OF THE INVENTION

For better understanding this invention is presented in two embodiments. The first embodiment of the building panel as illustrated in FIG. 1, is a structure of outer (11) and inner (12) plates, said outer plate for example of glass, and inner for example dry wall. Between plates (11) and (12) there is intermediate insulation space with optional thermal and/or sound insulation which preferably does not form a solid structure in connection with plates (11) and (12), for example vacuum panels, gas filled panels, melamine foam, nanofoam or aerogels. The connection (1) forms connection between plates (11) and (12). The connection (1) is implemented at least along the longitudinal part of panel frame.

In addition the connection (1) comprises the polymer-based profile (2) into which may be inserted additional profile (3) taking advantage of protrusions (6). Additives for lowering of thermal conductivity may be added to polymer out of which the polymer-based profile (2) is manufactured or said polymer component may be manufactured of polymer foam. Such additives should have thermal conductivity below 0.2 W/mK. The additives for lowering the thermal conductivity may be hollow mineral (glass, ceramic) or hollow polymer spheres. At least between plates (11) and (12) in the polymer-based profile (2) there is at least one thermally insulating pocket 4.

An adhesive (5) based on rubbery-elastic polymer is positioned between the polymer-based profile (2) and plates (11) and (12), this adhesive having hardness between 35 and 70 Shore A. Preferably the hardness of said adhesive is between 40 and 50 Shore A. The lower limit of adhesive hardness 35 Shore A stems from different adhesives known in structural glass facades which do not provide for stiffness of glass panels. In this invention said plates (11) and (12) provide for stiffness due to their distance and the adhesive should have as high stiffness as possible. The adhesives with hardness above 70 Shore A for sizes of building panels do not provide for sufficient compensation of mechanical stresses due to temperature dilatations of panel components. According to our own research the best compromise between higher stiffness and dilatation elastic is provided by adhesive with hardness between 40 and 50 Shore A.

The polymer-based profile (2) is preferably manufactured of extruded thermoplastic composite reinforced with 25% to 50%, preferably 40% of glass fibers by weight. The polymer-based profile (2) provides for bending rigidity of the panel. The thermoplastic polymers appropriate for use in civil engineering have relatively low modulus of elasticity ranging from 2000 to 3000 MPa. The polymer-based profile would therefore contribute little to stiffness (rigidity) of whole panel. In particular, the contribution is estimated at 10%. It would be economical that the polymer-based profile would contribute to stiffness. The thermoplastic composites with up to 55% weight filling with short or medium length glass fibers are state of the art. These may be up to five times stiffer than raw thermoplastics.

Our own research shows that the best choice are polyamide, polybutylene terephthalate, or polyethylene terephthalate thermoplastic with at least 25% weight filling of short glass fibers. Variants with over 55% of glass fibers are too demanding for the state of extrusion technology for profiles of 80 mm or more. For a profile size of about 100 mm and a wall thickness in range of 2 mm the filling of around 40% of glass fibers was found to be optimal from viewpoints of technological process and product properties. The achieved modulus of elasticity is around 7000 MPa. Termoplastic composites with less than 25% of glass fibers have excessive linear temperature expansions in direction of polymer-based profile (2) to be used in combination with adhesive (5) according to our own specification.

Such a polymer-based profile provides for stiffness of panels between 25-30%. The profile based on base of polymer (2) can be manufactured using a pultrusion process. In this case the polymer resin based on phenol-formaldehyde, polyester, preferably unsaturated, vinylester or epoxy, preferably with appropriate fillings, and can be pulled with glass or basalt fibers and appropriate woven or nonwoven mats of glass or basalt fibers through pultrusion matrix. In addition, some other fibers may be used. The process having significantly less than 50% of weight part of fiber content is here technologically not possible.

The upper limit of filling of fiber is again technologically limited and is around 75%. The achievable modulus of elasticity of the profile is here significantly higher and is in the range between 15000 and 25000 MPa. The pultrusion process is more demanding. The modulus of elasticity of the polymer-based profile is in this case so high that the required stiffness can be achieved without use of additional profile (3). The polymer-based profile (2) can provide within itself one or more thermally insulating pockets (4) filled with air or thermally insulating material. In the case of polymer-based extruded profile (2) there are usually more pockets and they tend to be small.

From viewpoint of prevention of convection of air and radiant heat transfer, filling of these insulation pockets with additional insulation usually is not necessary. In the case of pultruded polymer-based profile (2), preferably of thermosetting resin, the implementation with several insulation pockets is difficult. In such a case only one larger insulation pocket can be provided, however this should be filled with thermal insulation such as polyurethane foam.

Connection (1) further comprises adhesive (5) which is composite based on rubbery-elastic polymer, based on polyurethane, silicone, silane or preferably polysulfide. The composite adhesive (5) is further comprised of usual or special fillings such as calcite or other fillings to achieve desired properties. For achieving of appropriate panel temperature-dilatation resistance and providing for mitigation of errors in tolerances of the product the layer of adhesive (5) should be thick at least 1 mm. A thickness above 5 mm would significantly lower the stiffness of the panel, the best results are achieved at thicknesses between 2 and 3.5 mm.

An additional reinforcement profile (3) may be metal, preferably steel construction pipe. However, for purposes of lowering of heat transfer, the mineral materials may be used. It should be possible to use (for example) glued glass beams.

Referring to FIG. 2, the second embodiment of the building panel is a structure of outer (11) and inner (12) plates with intermediate insulation space. The connection (1) between plates (11) and (12) is provided at least along a longitudinal part of the panel frame. The connection (1) comprises two or more essentially one along another stacked spacers (7) which are attached one to another with at least one layer of polymer adhesive (8) with a hardness between 45 and 95 Shore A, preferably between 60 and 85 Shore A.

The spacers (7) can be metal rectangular tubes, with or without ribs preferably manufactured of thin stainless steel with heat conductivity lower than 16 W/mK. Such commercially available steel spacers known in state of the art of insulation glasses may be used. The spacers may be of hybrid construction with profile partially made of metal (stainless steel) and partially of polymer semi-rectangular tube such as hybrid (“warm edge”) spacers known in state of the art of thermally insulated glass. The spacers (7) may be also of elastic polymer foam or based on mineral, metal foam or honeycomb.

The best heat resistance is provided by implementation of hybrid spacer (7) with thickness of steel part of the spacer between 0.05 and 0.2 mm. The thicknesses below 0.05 mm are too thin for mechanical strength of the spacer, the thicknesses above 0.2 mm conduct too much heat. According to our own research the thickness of about 0.1 mm seems to be optimal. Due to particular properties of the system, as suggested in this patent application, for a polymer part of hybrid spacer of thickness of about 1 mm, polymers which are cheaper and conduct even less heat than those used in state of the art of insulation glasses may be used. These are for example, polyvinyl chloride (PVC) or polystyrene (PS). Insulation glasses usually use polycarbonate (PC) and polypropylene (PP).

The connection (1) in addition to spacers in the second embodiment comprises also adhesive (4) such as methacrylate or hybrid polyurethane. Similarly to the first embodiment of the panel, the hardness of said adhesive in combination with the thickness is of importance. To achieve appropriate stiffness of a stack of more than one spacer, a hardness of at least 45 Shore A is needed. A hardness of more than 95 Shore A could cause early shear failure of adhesive connection between plates (11) and (12) in corners when this connection is subject to outside forces (for example wind) in the corner of a building. The optimal is use of adhesive with final hardness between 60 and 85 Shore A, and a layer of adhesive between 0.1 mm and 1 mm. More than one layer of adhesive (e.g. two) can be used between spacers. Less than 0.2 mm combined thickness of adhesive between the spacers endangers the flexibility of the connection during exposure of the panel to wind, more than 1 mm of thickness does not provide sufficient stiffness. The thickness between 0.2 mm and 0.5 mm is optimal.

For the first implementation the hypothesis was tested whether the polymer adhesive fulfilling criterion from patent application W02004/073973 for adhesive to have tensile and/or shear strength greater than 2 MPa suffices for attaching of the system similar to one according to invention. On the panel of length of 1.4 m and width of 1 m, we used enameled float glass dark grey color manufactured by local manufacturer Reflex (Reflex d.o.o., Podgrad 49250 Gornja Radgona, Slovenia) as outer plate (11), said plate 8 mm thick. The inner plate (12) was 15 mm thick plate Rigidur H of manufacturer Rigips (Saint-Gobain Rigips GmbH, Schanzenstraβe 84, 40549 Düsseldorf Germany). The panel was equipped with two polymer-based profiles (2) along longitudinal sides of the profile according to FIG. 1.

The polymer-based profile (2) was 100 mm wide and 43 mm thick. It was manufactured of polyamide 6.6 GF40. Into polymer-based profile (2) a standard steel rectangular profile (3) was inserted, said profile having dimensions 50×30×2.5 mm. The adhesive between polymer-based profile (2) and plates was polyurethane, namely 1 part of isocyanate and 4 parts of polyol. Isocyanate was Suprasec 5025 of manufacturer Huntsman (Huntsman Advanced Materials 10003 Woodloch Forest Drive 77380 The Woodlands, Tex. USA), the polyol was Mitopur A1/5 of local manufacturer Mitol (MITOL, tovarna lepil, d.d., Se{hacek over (z)}ana Partizanska cesta 78 SI-6210 Se{hacek over (z)}ana, Slovenija). The adhesive had modulus of elasticity of approximately 2500 MPa and tensile strength much higher than 2 MPa.

For insulation core of the panel, a styrofoam of 100 mm thickness was used. Before attachment, the polymer-based profile (2) was prepared for improved grip with adhesive. Prepared panels were built into the experimental building. After approximately 60 days of summer weather at a geographical latitude of approximate 45° the outer plates (11) started to fall off. With this experiment we have proven that the criterion of strength of adhesive above 2 MPa is not decisive for use of appropriate adhesive in system such as presented here.

For the second implementation, the panel using only the second embodiment according to this invention was used. For panel of length 1 m and width 0.5 m, we used enameled float glass dark grey color manufactured by local manufacturer Reflex as outer plate (11), said plate 8 mm thick. The inner plate (12) was 15 mm thick plate Rigidur H of manufacturer Rigips. For spacers (7) the modified spacers Chromatech Ultra manufactured by Rolltech (ROLLTECH A/S, W. Brüels Vej 20, DK-9800 Hjørring, Demnark) of nominal height 20 mm were used. The polymer part of the spacer was manufactured of polystyrene. The stack was comprised of 5 rectangular spacers, said spacers continuous around whole perimeter of the panel, said spacers having aluminum foils positioned between themselves as the panel was gas filled. Between the spacers, and spacers and plates the structural adhesive SikaFast 3131 manufactured by Sika (Sika Deutschland GmbH, Kornwestheimerstrasse 107, Pforte 1, Stuttgart 70439,Germany) was used having thickness 0.3 mm. The adhesive has hardness 80 Shore A. Such a panel has appropriate stiffness for lengths up to 3 m for building up to one story high buildings.

For the third implementation both embodiments were used together. For 10 panels of length 2.6 m and width of 1 m, we used transparent tempered float glass manufactured by local manufacturer Reflex as outer plate (11), said plate 8 mm thick. The inner plate (12) was 15 mm thick plate Rigidur H of manufacturer Rigips. For spacers (7) the modified spacers Chromatech Ultra manufactured by Rolltech of nominal height 20 mm were used. The polymer part of the spacer was manufactured of polystyrene. The stack was comprised of 5 rectangular spacers said spacers continuous around whole perimeter of the panel, said spacers having aluminum foils positioned between themselves as the panel was gas filled. Between the spacers, and spacers and plates the structural adhesive SikaFast 3 13 1 manufactured by Sika was used having thickness 0.3 mm.

The panel was equipped with two profiles on base of polymer (2) along longitudinal sides of the panel according to FIG. 1. The polymer-based profile (2) was 100 mm wide and 43 mm thick. It was manufactured of polyamide 6.6 GF40. Into polymer-based profile (2) standard steel rectangular profile (3) was inserted, said profile having dimensions 50×30×2.5 mm. The adhesive between polymer-based profile (2) and plates (11) and (12) was polysulfide adhesive GD 116 manufactured by Komerling chemische fabrik (KÖMMERLING Chemische Fabrik GmbH, Zweibrücker Str. 200, D-66954 Pirmasens, GERMANY), having a hardness of 38 Shore A and 3.5 mm thick. Before attachment, the polymer-based profile (2) was treated for improved grip using process of plasma treatment. The described panels were thoroughly examined from viewpoints of stiffness and strength. Strength wise, the panel withstood a wind load of up to 35 kN. Stiffness wise the panel withstood wind load of 12 kN or 4.6 kPa wind induced stress at nominal deflection of inner plate (12) of L/200=13 mm. This corresponds to stagnation pressure of wind blowing at 85 m/s or 306 km/h. The panels were additionally exposed to 1000 cycles of similar wind load, and built into an experimental building where they underwent realistic tests with temperature induced stresses. 

We claim:
 1. The building panel comprising a panel having an outer (11) plate and an inner plate with an intermediate insulation space, characterized in that the connection (1) between the outer plate (11) and inner plate (12) is implemented at least along a longitudinal part of a panel frame where the connection (1) comprises at least: a. polymer-based profile (2) whereas inside the polymer-based profile (2) between the plates (11) and (12) there is at least one thermal insulation pocket (4); b. an adhesive (5) based on rubbery-elastic polymer between the polymer-based profile (2) and outer plate (11) and inner plate (12) wherein the nominal hardness of the adhesive (5) is between 35 and 70 Shore A; c. outer plate (11) and inner plate (12) with a side frame providing for stiff box structure of building panel, said building panel further comprising an insulation core.
 2. The building panel according to claim 1, characterized in that the polymer-based profile (2) is manufactured of extruded thermoplastic composite reinforced with 25% to 55% by weight.
 3. The building panel according to claim 2, characterized in that the polymer-based profile (2) is manufactured on base of one or more of a polyamide, polybutylene terephthdate, and polyethylene terephthalate.
 4. The building panel according to claim 1, characterized in that the polymer-based profile (2) is manufactured of pultruded thermosetting composite reinforced with 50% to 75% by weight of fibers, said fibers comprising or more of glass, basalt, appropriate woven, mats, and nonwoven mats.
 5. The building panel according to claim 4, characterized in that the polymer-based profile (2) is manufactured of one of phenol-formaldehyde, polyester, vinylester, and epoxy, with appropriate fillers.
 6. The building panel according to claim 1, characterized in that into the material of the polymer-based profile (2) the additives with thermal conductivity lower than 0.2 W/mK are added.
 7. The building panels according to claim 1, characterized in that the adhesive (5) is composite based on one of polyurethane, silicone, silane, and polysulfide with thickness of adhesive (5) of 1 mm to 5 mm.
 8. The building panel according to claim 1 characterized in that an additional profile (3), made of one of metal or mineral, is inserted into the polymer-based profile (2).
 9. A building panel comprising an outer (11) plate and an inner (12) plate with intermediate insulation space, characterized in that a connection (1) between the outer plate (11) and the inner plate (12) is implemented at least along the longitudinal part of a panel frame where the connection (1) comprises at least two essentially one along another stacked spacers (7) attached one to another with at least one layer of polymer adhesive (8) with hardness between 45 and 95 Shore A, preferably 60 and 85 Shore A, and whereas outer plate (11) and inner plate (12) together with the panel frame provide for stiff box structure of the building panel.
 10. The building panel according to claim 9, characterized in that the spacers (7) are either metal tubes, preferably rectangular or partially metal partially polymer tubes, preferably rectangular or profiles of rectangular cross section of polymer, mineral or metal foam or honeycomb or combination thereof.
 11. The building panel according to claim 10, characterized in that the spacers (7) are partially metal partially polymer tubes whereas the metal part is manufactured from stainless steel sheet thickness between 0.05 mm to 0.20 mm.
 12. The building panel according to claim 10, characterized in that the spacers (7) are partially metal partially polymer tubes whereas the polymer part is manufactured of thermoplastic polymer-based on polyvinyl chloride or polystyrene of thickness of around 1 mm.
 13. The building panel according to claim 9, characterized in that the polymer adhesive (8) comprises one or more of methacrylate and hybrid polyurethane.
 14. The building panel according to claim 10, characterized in that each layer of polymer adhesive (8) has approximate average thickness of 0.2 mm to 1 mm.
 15. The building panel of claim 1, wherein the nominal hardness of the adhesive (5) is between 40 and 50 Shore A;
 16. the building panel of claim 2, characterized in that the polymer-based profile (2) is manufactured of extruded thermoplastic composite reinforced with substantially 40% by weight of glass fibers.
 17. The building panel according to claim 1, characterized in that the polymer component of material of the polymer-based profile (2) is a polymer foam.
 18. The building panels according to claim 1, characterized in that the adhesive (5) is composite based on one of polyurethane, silicone, silane, and polysulfide with thickness of adhesive (5) of 2 mm to 3.5 mm.
 19. The building panel according to claim 11, characterized in that the spacers (7) are partially metal partially polymer tubes whereas the metal part is manufactured from stainless steel sheet thickness substantially 0.10 mm.
 20. The building panel according to claim 10, characterized in that each layer of polymer adhesive (8) has approximate average thickness of 0.3 mm to 0.5 mm. 